Long-carbon-chain nylon is a high-performing and high-value chemical material due to its unique thermal, physical, chemical and mechanical properties. Nylon 12 is a specialty resin designated for making fuel lines and brake systems. For high-grade Nylon 12, the price is usually more than 15 euros/kg. Analysis of a fatal explosion at a German plant of the world's largest Nylon 12 supplier, Evonik, revealed that explosion caused by contact between a highly active catalyst (Et2AlCl) and water is a major risk factor. Thus, there is a need for a safe process for producing long-chain dicarboxylic acids.